In Jewish mythology, the name Leviathan can refer to a variety of monstrous creatures, including a primordial sea serpent, a dragon, a snake, a crocodile, or a whalelike animal. It likely developed from pre-biblical Middle Eastern mythology, especially that of the sea monster in the Ugaritic myth of Baal. Leviathan appears in several books of the Hebrew Bible (Old Testament).

The name Leviathan comes from the Hebrew Livyatan, which comes from a root that means “to twist, turn, wind, or coil.” Today the name is often used to refer generally to a sea monster or to any gigantic powerful thing.

In one psalm, Leviathan is a whalelike creature, perhaps embodying the wonder and strangeness of creation. In the Book of Isaiah, Leviathan is a sea serpent symbolizing Israel’s enemies. In the Book of Job, Leviathan is a fire-breathing crocodile, perhaps personifying an aspect of creation that is beyond human comprehension or control.